rtc - try implementing RTC / kernel: removed rt from the codebase (released separately)

kernel/src/sys/arch/x86_64/idt.c

@@ -41,6 +41,7 @@ void idt_init() {
 
   pic_init();
   pic_unmask_irq(1);
+  pic_unmask_irq(8);
 
   __asm__ volatile("lidt %0" : : "m"(idtr)); // load the new IDT
   __asm__ volatile("sti");                   // set the interrupt flag

kernel/src/sys/arch/x86_64/interrupts.c

@@ -45,7 +45,7 @@ void exception_handler(registers_t *regs) {
 
     log("ints - keyboard\n");
   } else if (regs->int_no == 32 + 8) {
-    rtc_handle_interrupt(regs);
+    log("rtc\n");
   } else if (regs->int_no == 0x80 - 32 || regs->int_no == 32) {
     pit_handler(regs);
   } else if (regs->int_no == 0x80) {

kernel/src/sys/arch/x86_64/rtc.c

@@ -1,28 +1,41 @@
-#include "sys/arch/x86_64/idt.h"
-#include "sys/arch/x86_64/io.h"
-#include <sys/arch/x86_64/pic.h>
-#include <sys/arch/x86_64/rtc.h>
-#include <sys/printf.h>
+#include "rtc.h"
+#include "io.h"
 
-void rtc_init() {
-  asm("cli");
-  outb(0x70, 0x8A);
-  outb(0x71, 0x20);
-  asm("sti");
+char bcd;
 
-  asm("cli");            // disable interrupts
-  outb(0x70, 0x8B);      // select register B, and disable NMI
-  char prev = inb(0x71); // read the current value of register B
-  outb(0x70,
-       0x8B); // set the index again (a read will reset the index to register D)
-  outb(0x71, prev | 0x40); // write the previous value ORed with 0x40. This
-                           // turns on bit 6 of register B
-  asm("sti");
-
-  // pic_unmask_irq(8);
+unsigned char read_register(unsigned char reg) {
+    __asm__ volatile("cli");
+    outb(RTC_COMMAND, reg);
+    return inb(RTC_DATA);
+    __asm__ volatile("sti");
 }
 
-void rtc_handle_interrupt(registers_t *regs) {
-  (void)regs;
-  printf("RTC!\n");
+void write_register(unsigned char reg, unsigned char value) {
+    __asm__ volatile("cli");
+    outb(RTC_COMMAND, reg);
+    outb(RTC_DATA, value);
+    __asm__ volatile("sti");
+}
+
+unsigned char bcd2bin(unsigned char in_bcd) {
+    return (bcd) ? ((in_bcd >> 4) * 10) + (in_bcd & 0x0F) : in_bcd;
+}
+
+int rtc_init() {
+    __asm__ volatile("cli");
+    unsigned char status;
+    status = read_register(RTC_STATUS);
+    status |= 0x02;         // 24 hour clock
+    status |= 0x10;         // update ended interrupts
+    status &= ~0x20;        // no alarm interrupts
+    status &= ~0x40;        // no periodic interrupt
+    bcd = !(status & 0x04); // check if data type is BCD
+    write_register(RTC_STATUS, status);
+
+    outb(0x70, 0x8B);		// select register B, and disable NMI
+    char prev=inb(0x71);	// read the current value of register B
+    outb(0x70, 0x8B);		// set the index again (a read will reset the index to register D)
+    outb(0x71, prev | 0x40);	// write the previous value ORed with 0x40. This turns on bit 6 of register B
+    __asm__ volatile("sti");
+    return 0;
 }

kernel/src/sys/arch/x86_64/rtc.h

@@ -1,6 +1,18 @@
-#pragma once
+#ifndef __TIME_H
+#define __TIME_H
 
-#include "sys/arch/x86_64/idt.h"
+#define RTC_COMMAND         0x70
+#define RTC_DATA            0x71
+#define RTC_STATUS          0x0B
 
-void rtc_init();
-void rtc_handle_interrupt(registers_t *regs);
+#define RTC_SECONDS         0x00
+#define RTC_MINUTES         0x02
+#define RTC_HOURS           0x04
+#define RTC_DAY_OF_WEEK     0x06
+#define RTC_DAY             0x07
+#define RTC_MONTH           0x08
+#define RTC_YEAR            0x09
+
+int rtc_init();
+
+#endif // __TIME_H__